Relaxation therapy for essential hypertension: specific or nonspecific effects?

This study investigated the role of nonspecific treatment factors in the behavioral control of essential hypertension. Forty-eight subjects with mild hypertension were randomly assigned to one of three conditions: (1) subject-alone relaxation therapy; (2) couples-relaxation therapy; or (3) couples-cognitive therapy. The third condition, which provided instruction in cognitive methods of stress reduction, controlled for the effects of positive treatment expectancy and other nonspecific factors. At the end of 8 weeks, subjects in all three conditions showed significant reductions in systolic and diastolic blood pressure, which were maintained at 1 and 5 months post-treatment. However, no significant differences in effectiveness were observed among conditions at any assessment period. Although the results of this study did not unequivocally demonstrate that a positive treatment expectancy is a sufficient condition for blood pressure reduction, they do raise questions concerning whether relaxation therapy is a necessary condition.